1. Technical Field
The present invention relates to a heat-radiating substrate and a manufacturing method thereof.
2. Description of the Related Art
Recently, efforts for manufacturing various types of heat-radiating substrates using metal having good thermal conductivity has been made to remove problems in heat radiation of power elements and power modules that are applied in a variety of fields. Further, heat-radiating substrates with a multilayer micro pattern have been required for other products as well as LED modules and power modules.
However, for organic PCBs, ceramic substrates, glass substrates, or heat-radiating substrates including a metal core layer in the prior art, it is relatively difficult to form a micro pattern and the cost is high, as compared with silicon wafers, such that the application field has been limited.
For example, according to a method of manufacturing a printed circuit board of the prior art, a copper clad laminate (CCL) having a copper foil on a pre-preg is prepared first. Next, a vertical via-hole is formed by a mechanical drill bit to connect the layers and then an electroless plated layer is formed on the copper clad, including the inner wall of the vertical via-hole.
Thereafter, an electrolytic plated layer is formed on the electroless plated layer, including the inside of the vertical via-hole, by the electrolytic copper plating (fill plating). A circuit layer including a via is formed by patterning the copper foil, the electroless plated layer, and the electrodeposited layer.
Meanwhile, a heat-radiating substrate including a metal core layer is formed by using a metal core layer instead of the copper clad laminate.
Thereafter, a multilayer printed circuit board is manufactured by forming a build-up layer on the circuit layer. The build-up layer is formed by sequentially stacking circuit patterns formed by plating and printing, and insulating materials.
The printed circuit board (or heat-radiating substrate) of the prior art which was formed by the above method according to the prior art had a problem that it is hard to form a micro pattern and heat-radiating properties are deteriorated. Further, the multilayer printed circuit board (or multilayer heat-radiating substrate) of the prior art had a problem that the thickness of the printed circuit board was increased by the thickness of the build-up layer. Therefore, there was a problem that it takes a long time for the multilayer printed circuit board to process signals due to the large length of the wire, and as a result, it negates the requirement of high-integrated wiring.